title: Modulation of estrogen receptor alpha activity and expression during breast cancer progression.
abstract: Seventy percent of breast tumors express the estrogen receptor (ER), which is generally considered to predict a better outcome relative to ER-negative tumors, as they often respond to antiestrogen therapies. During cancer progression, mammary tumors can escape from estrogen control, resulting in the acquisition of invasive properties and resistance to treatment. ER expression is a dynamic phenomenon and is finely regulated at numerous levels, including the gene, mRNA, and protein levels. As a consequence, many molecular mechanisms have been implicated in modulating ER activity and estrogen signaling in mammary cancer. In fact, one-third of ER-positive breast cancer cells do not respond to first-line endocrine therapies, and a large subset of relapsing tumors retain ER expression. Increased knowledge of these mechanisms has led to the development of better prognostic methods and targeted therapies for patients; however, additional research is still needed to improve patient survival. In this chapter, we focus on the signaling pathways leading to changes in or loss of ER activity in breast cancer progression.
authors.affiliation: Institut de Recherche en Santé-Environnement-Travail-IRSET, University of Rennes 1, INSERM U1085, Team TREC, Biosit, Rennes, France.
authors.forename: Gwenneg
authors.initials: G
authors.lastname: Kerdivel
authors.forename: Gilles
authors.initials: G
authors.lastname: Flouriot
authors.forename: Farzad
authors.initials: F
authors.lastname: Pakdel
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism*; D049109:Cell Proliferation; D019175:DNA Methylation; D047628:Estrogen Receptor alpha / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D035683:MicroRNAs / Q000378:metabolism; D009154:Mutation; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D017978:Receptors, Growth Factor / Q000378:metabolism; D015398:Signal Transduction
chemical_list: C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha; D035683:MicroRNAs; D009363:Neoplasm Proteins; D017978:Receptors, Growth Factor